


robot [redacted]

by dirtmemer



Category: Uta no Prince-sama
Genre: M/M, ai forgot his dick, ai keeps making weird fetish jokes, ai thinks ranmaru is big stupid, birthday fic for the birthday boy!!!, dubious robot genitals, everyone else shows up for a hot second, is he wrong?, ranmaru is being bullied, this is honestly shameless porn, very shameless
Language: English
Status: Completed
Published: 2019-03-01
Updated: 2019-03-01
Packaged: 2019-11-07 08:31:22
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,006
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17957144
Author URL: https://archiveofourown.org/users/dirtmemer/pseuds/dirtmemer
Summary: The thing about Ai's birthday is the thing about all birthdays: loud congratulations, ducking, wincing, shouting.





	robot [redacted]

**Author's Note:**

> shameless birthday porn for one shameless robot!! of course its ranai u think i can write anything else ??? the answer is no

The thing about Ai's birthday is the thing about all birthdays: loud congratulations, ducking, wincing, shouting. Objects crashing to the ground. Gifts he didn't ask for shoved into his arms carelessly, numerous people trying to strangle him with their chokehold hugs, Natsuki's unviable attempts at poisoning him. Someone would inevitably do something extremely stupid, and the day would be over. 

On this particular birthday, he holds the same slow, mullish dread that someone would inevitably do something extremely stupid. But it is a clear taunt to Ai's brittle pride when nothing particularly special happens. The cake is there, the presents are numerous, the song a harmonious evil belted out by at least seven people with mindless glee. Reiji tries to strangle him lovingly, then passes him off to Ren. Camus scarfs down half of the cake, holding his fork in a white-knuckled grip. Everything is normal, if a little chaotic. 

All these events lead Ai to the same conclusion: if his birthday was some kind of groundhog loop of stupidity, then eventually, _eventually_ , someone would do something incredibly stupid. It is only a matter of who, when, and how. After all, a few birthdays ago, Otoya had set fire to the birthday cake while trying to light the candles. If he closes his eyes, he can still envision the aftermath where Camus still demolished the cake, regardless of the dancing flames on his fork, while Ai dove for the fire extinguisher. 

The conclusion that Ai comes to leads him to yet another conclusion: if his birthday remains a groundhog loop of stupidity, then he might as well take matters into his own hands. His own very capable, logical hands. Ai wouldn't set fire to anything. He also wouldn't break a collector's edition item that he spent months tracking down online. He still hasn't forgiven Syo for that. 

Amidst the birthday caterwauling, Ai slips to the kitchen where Ranmaru is hiding from social interaction, hauls him up by the lapels of his shirt and kisses him. 

"Hrrgh?" Ranmaru says. 

"I must confess that I sometimes want to hold you in my loving embrace," Ai says. 

Ranmaru makes a bewildered, questioning noise, and kisses Ai back. His mouth is warm. Ai feels like a particularly mediocre genius for choosing this exact moment to confess his grave sentiments. 

"What the fuck," Ranmaru says, finally. His eyebrows are scrunched in angry confusion. "Are you coming on to me?" 

"What makes you think that?" Ai says. His hand settles on Ranmaru's crotch. 

"Your hand—" Ranmaru splutters. 

"Is on your dick, yes." 

"That's—" 

"Good? Bad? Makes you want to go somewhere private with me and take off all our clothes?" 

"The last one," Ranmaru says, slowly, considering. "Why're you so eager?" 

"Because," Ai says, turning his head to lick a long line across Ranmaru's jaw, "it's my birthday." 

Ranmaru's hands land on Ai's waist. From the depths of the living room, someone howls in outraged delight. 

"Sounds like they've gotten into the alcohol," Ranmaru says, contemplative. "Maybe if we use the back door and climb a tree, we can get to the second floor without anyone noticing." 

"Or," Ai says, logically, using his logic, "we could just walk up the stairs while everyone is distracted." 

"Or we could do that," Ranmaru agrees easily. "Good plan. Let's go and find somewhere private to take all our clothes off, then." He plants a swift lick against the shell of Ai's ear. It feels tingly. 

Ai grabs his hand and hauls him out of the kitchen. Outside lies a battlefield of spilled alcohol and nine loud, drunk men. He peers around the corner warily. Ranmaru bumps into his back and makes a startled little noise. 

Ai assesses the scene. Reiji, howling with mad laughter, his back turned to the staircase, his hands in Camus's hair. Camus, kneeling over Ren's prone sprawl, fingers digging into his ribs. Ren, being tickle-murdered by Camus. Masato and Tokiya curled up on the couch, gesturing to the ceiling for no apparent reason. Otoya and Syo, doing push ups, also for no apparent reason. Natsuki, cheering Otoya and Syo on. Cecil, napping face down in one corner. All of them are conveniently angled away from the stairs. Most of them have drinks in their hands. Ai only prays that none of them spill any on the carpet. 

Ai tries to exchange a meaningful glance with Ranmaru, but any meaning is lost on him. Ranmaru blinks at him blankly, until Ai says, "We should run," and they book it across the frontier of alcohol induced chaos up the stairs into Ranmaru's room, slamming the door shut behind them. 

"Guess they didn't notice," Ranmaru says, already yanking his shirt off. "Hey, what—" 

Ai reaches his hand into Ranmaru's pants. Ranmaru's mouth slams shut as Ai curls his fingers around his limp dick. 

"If it's not clear," Ai says, "I want you to use this—" a casual squeeze of his hand; Ranmaru squeaks, flushing down his neck, "—to fuck me." 

"Got it," Ranmaru says, shakily. "My dick is at your command? Please—ow, _ow_ , not so hard!" 

He says that, but the dick under Ai's hand is plumping up all the same. 

Ranmaru rests his warm head on Ai's shoulder. "You're so goddamn disrespectful to your elders." 

"Today's my birthday, so it's fine." 

Ranmaru scoffs. Then his irritation melts into curiosity. "Wait, do you—do you have a robot dick? An ass—" 

"I forgot to put it on today," Ai interrupts. "And I have a hole. Just one. I don't have any waste products to excrete—" 

"Lemme see!" Ranmaru tackles Ai onto the bed. "Take off your pants, take off your pants—" 

Ai lifts his hips obligingly when Ranmaru shoves his pants down. Ranmaru catches his legs, one in each hand, spreading them apart. His fluffy grey head bends right down, and Ai startles when Ranmaru licks the inside of his left thigh. 

"Hot," Ranmaru declares, squinting critically down at Ai's... everything. "Too bad you forgot your dick. My blowjobs will literally blow your mind." 

"Next time," is all Ai can say, before Ranmaru shoves his thighs up and out of the way and puts his mouth where Ai really wants him to put his mouth. Dull pleasure. Ai forgot that he's turned his sensitivity down in preparation for the birthday strangling process. He sharpens it back up a little, and—oh, much better—the warmth of Ranmaru's mouth, the soft tickling sensation of his hair against Ai's thighs, the stick of Ai's shirt against his back, the soft sheets giving way under his hands as he curls his fingers. 

"Oh," Ai breathes, head falling back against the mattress when Ranmaru slips a finger inside. "Ah, that feels nice." 

Ranmaru pulls off with a wet slurp. He looks offended. "Nice? I eat you out and the praise I get is a mediocre _nice_ —"

Ai throws his head back and bares his throat with such a loud moan Ranmaru looks rattled for a brief moment. He looks ridiculous, eyes wide and wary, Ai's slick glistening down his chin. 

"What are you—" 

"Ranmaru," Ai whimpers, arching his back and curling his toes, "Ranmaru, you make me feel so _good_." 

"Oh my god." 

"More," Ai flutters his lashes at Ranmaru, "More, please—fuck me until I can't walk, tear me open and—" 

"Holy shit." Ranmaru's ears are red. "Holy shit, okay, I was joking, please don't get into the gore." 

Ai laughs. He tilts his head and peers at Ranmaru, smug satisfaction flickering through his chest. "I was only joking about half of it." 

"Hope it was the gore half," Ranmaru mutters, mouth twisted into a scowling kind of smile. "You're already wet as hell and dripping down my fingers, and you're still so smug. Brat. How come you get wet, anyways?" 

Ai curls his legs around Ranmaru's waist. "Self lubricating mechanism," he explains, then, "Why don't you shut me up?" Ranmaru's smile is slow and wide, all teeth and narrow eyes. 

"Yessir," Ranmaru drawls lazily. He rocks up between Ai's legs, his body warm against Ai's front. Another finger, a more insistent thrust. The way Ranmaru curls his fingers has Ai curling his toes in real satisfaction. 

Ai sighs. He lets his thighs fall slack around Ranmaru's hips. Ranmaru kisses the side of his neck, pulls his hair gently to bare his throat, leaves soft bites against his skin, his teeth gentle pinpricks of pressure. One of Ai's thighs is pressed up against Ranmaru's chest, knee thrown over his shoulder. Ranmaru fucks Ai with two fingers, then three, stretches his fingers apart and chuckles when Ai gasps. 

"Good?" A murmur against his sweaty cheek. 

Ai turns his head for a kiss instead of answering. Ranmaru's erection presses against his thigh, his fingers rocking in-out in a slow, steady gentle rhythm. Ranmaru is more careful than Ai's ever expected him to be. He lips at the junction between Ai's neck and shoulder, fingers pressing and spreading against somewhere really, really good. Ranmaru watches him through his quiet orgasm, bright-eyed and smirking as Ai trembles against him. 

"Good?" The same question, but in a different timbre. Ranmaru's voice takes up a rasp, punctuated with the rocking of his hips, the grinding of his jeans against Ai's sensitive skin. 

"Pants," Ai says instead. He opens his eyes (when did he close them?), meets Ranmaru's narrow smile. Ranmaru dips his head and obliges, tugging his pants off. Ai lifts a hand to pat his dick. His pubic hair is dark. 

Oh. Ranmaru's dick retreats from his reach. He's licking down Ai's thighs again. It feels nice. Warm. Ai's soft from his orgasm, pliant with Ranmaru's touch. He turns his head to one side, closing his eyes again when Ranmaru's tongue licks into him. 

"Ah," Ai whines. "Ranmaru—" 

A hint of teeth. Ranmaru's sharp grin, pressing against all the right places. Hot, wet noises—Ranmaru's enthusiastic slurping and Ai's soft moans, the quiet slide of skin against bedsheets. 

Ai catches a fistful of hair, tugging. "Wait, stop, stop—" 

Ranmaru stops. He's breathing heavy, running his tongue along his teeth, and he bends his head, asks, "What's the matter?" all concerned, his thumbs rubbing gentle circles into Ai's hips. 

"I want—" Ai says, "—fuck me." 

Ranmaru blinks. His pupils are blown wide, heart rate too fast, body temperature too high, breathing too hard. For a moment they just look at each other, then Ai's thighs are hauled up around Ranmaru's waist, a hand stroking shakily at Ai's hair, and then—

It hurts first, the slow push of Ranmaru's dick inside him, like pulling a muscle, a hot sharp ache. Ranmaru is good about it, going slow, pressing down gently. Ai's chest strains with the gasps he takes, legs trembling. 

"Okay?" A kiss pressed to the corner of his eye. Ranmaru's breath fanning across his cheek, warm and sticky. 

"Keep going," Ai says. He likes the slow burn, the shape of Ranmaru's dick spreading him open. It feels good, intense, pressure inside him and on top of him where Ranmaru is pushing him down, still pushing in, deeper, deeper— 

Ranmaru huffs into his ear. It's a drawn out sound, weak and shaky, like he's been punched in the gut. "Tight," he says, babbling, "feels good, so _hot_ —you okay?" 

"I feel," Ai says, slowly, "like you're rearranging my wiring from inside out." 

The look of alarm on Ranmaru's face is slightly worth it. "What—" 

"You're so big," Ai continues, enjoying Ranmaru's apprehension, "it feels like you're fisting me with your dick." 

Ranmaru's perturbation melts into his usual scowl. "Ai, you fucking—why do you keep trying to ruin the mood?" 

"I like joking." Ai pulls Ranmaru down for a wet kiss. Ranmaru bites his mouth for his trouble. 

"Gore jokes, fisting jokes," Ranmaru grumbles, but he presses up against Ai anyways, belly to belly, his abs sliding pleasantly against Ai's skin. "What's next? You gonna start yowling like a cat and call me a furry?" 

"I might," Ai blinks up at Ranmaru and smiles his most charming smile. "For now, though... I'll just stick to calling you a vandal. For repositioning my—" 

"Okay, yeah, got it," Ranmaru rolls his eyes. He punctuates his sentence with a gentle roll of his hips. "This good?" 

"You can go harder," Ai murmurs. He slicks Ranmaru's fringe back from his forehead. "Fuck me like you mean it." 

Ranmaru's brows furrow. "I don't know what that means, but okay." 

Ai really—he really does like Ranmaru's intense bouts of stupidity. Amusement burns through him, possesses him to cross his wrists neatly at the back of Ranmaru's neck. He bares his throat politely, closing his eyes when Ranmaru scrapes his teeth against his pulse. 

Pressed together, almost nose to nose. Ranmaru seems to like this particular position: Ai's legs in the air, arms around Ranmaru's neck. A few gentle thrusts. Ai remains unimpressed until Ranmaru put a little more force into it, kissing his frown away. 

"That's more like it," Ai sighs. Ranmaru follows up with a bout of relentless thrusting, harsh pressure, a constant back-and-forth. Ranmaru's breathing goes erratic, wild to match the rhythm of his hips. 

"Feels good," Ranmaru gasps, his hips rolling rolling rolling. He slams in deep, unrelenting, folding Ai in two under his weight. "Oh fuck, you're so—" 

Noisy. Ranmaru's babbling, his warm mouth pressed against the shell of Ai's ear. A hand in his hair, catching a handful at the nape of his neck, forcing his head back further. Ranmaru's body all heat against his front. Warm inside him, hot— Ranmaru's dick spreading him open in a really good way, just the right pressure, the pleasure white-hot, tingling up his spine. He's not sure his circuits can take so much, so fast—he's heating up from the inside out. 

Ai tries vainly to regulate his breathing. Intake of oxygen, exhale of everything else. It's shaky; his throat works around his quiet moans, caught under Ranmaru's grip. He watches the way Ranmaru's muscles work under his skin, rolling and coiling together, contract relax contract relax, powerful. 

Lips against his throat. Teeth scraping down his skin, tongue drawing lines through the damp sweat-stick. Heat, more heat. Ranmaru pushing his body down hard enough to drive the breath out of him. Ranmaru hisses through his teeth, expression scrunched in a feral snarl, breathing hard. 

"Ah," Ai manages quietly, "Feels nice." 

"Again," Ranmaru rasps, making some kind of breathy, throaty noise, "again with the nice." 

"Feels good," Ai murmurs, lifting his hips obligingly when Ranmaru claws at them, lifting until Ai rests on his shoulder blades, angling them up, thrusting down like he's trying to hammer Ai into the bed. " _Ohh_ —" 

The bed keeps thudding against the wall. The squeak of bedsprings, Ranmaru's movements growing frenzied, staying deep like he doesn't want to pull out more than two inches ever; he fills Ai up with his dick and his presence and the affectionate bites he leaves on Ai's skin. Ai shivers. 

"Close," Ranmaru whines. His mouth finds a spot on Ai's shoulder, licking, kissing. "Close, close, I'm gonna—" 

He bites. Ai trembles, legs tightening around Ranmaru, clamping down, the only warning Ranmaru gets before he comes with a soft _oh_. Ranmaru chases after him, panting around his teeth in Ai's skin, fingers digging into Ai's hips, thrusting hard and fast until he licks the indent he made on Ai's shoulder and says, "Ah— _fuck_ , where—where do I—" 

Ai laughs. He sounds dazed, his body shuddering from Ranmaru's frantic movements. Ai strokes a hand down his damp belly, "Inside, why not—inside, mark me as _yours_ —" 

" _Fuck_ ," Ranmaru says, nearly a howl, and comes shuddering inside him. He slumps warm and heavy on top of Ai, eyes closing. It feels nice. Safe. 

A stutter of breath. Ranmaru lifts himself up onto his elbows and kisses Ai's cheek politely. "You okay?" 

"Mmh," Ai says, lazy. "This was stupid." 

Sudden tension. Ranmaru tenses up against him, and Ai tenses too, in reaction. Then he relaxes back into his sprawl, cracks an eye open to look at the hurt on Ranmaru's face. 

"You're misunderstanding," Ai says. He tugs Ranmaru down for a kiss, and the hurt melts away into petulant confusion. "I meant—confessing to you in the chaos that was—my _birthday party_. We should go on a date tomorrow. Do everything properly." 

Ranmaru opens his mouth. Closes it. Brows furrowed like he's deep in thought, and he says, "Can you even walk tomorrow?" 

Ai slaps him lightly, catching his ear. Ranmaru yelps, pained. "Don't overestimate yourself, Ranmaru." He's so stupid. This is why he's Ai's favorite. "Please pull out." 

"Oh," Ranmaru blinks. His soft dick slips out with a small gush of come. They both shudder. "Wow." 

Ranmaru flops on his side. He curls his arm across Ai's waist, nuzzling into his shoulder affectionately. "Hey, so—this means you like me." 

Ai closes his eyes peacefully. "Stop talking." 

"But you like me." 

"Yes, but stop talking." 

Ranmaru laughs. "Guess what," he confides, kissing Ai's neck, "I like you too." 

Oh god. Ranmaru is so— he's just so _stupid_ sometimes. Ai feels an irrational rush of warm affection, spreading through his body. Or maybe that's the cum leaking out of him. 

"Now that we've established that we like each other," Ai says, trying to school his expression into passive indifference, "I'm going to ignore you." 

Ranmaru stays silent in uncharacteristic obedience. Ai opens his eyes in wary caution just in time to get the brunt of Ranmaru blowing a loud, wet raspberry into his belly. Ai screeches, rearing his legs up for a kick—Ranmaru cackles and scoops his pants off the floor, tripping out of the room, leaving Ai to sulk in annoyed silence. 

He slinks back later with a damp cloth. It's warm as he cleans Ai gently. "Hey," Ranmaru says. He presses tiny kisses to Ai's shoulder. "Happy birthday." 

Ai continues ignoring him. Still, he reaches out for Ranmaru's free hand and laces their fingers together.

**Author's Note:**

> ¯\\_(ツ)_/¯ 
> 
>  
> 
> [ my tumblr ](maru-man.tumblr.com)


End file.
